I know that if an application is in the sleep state, When a signal is catched, it will be processed by the handler. But what happens if it's processing something?
Not so, really
take this example program
If you do run the program in two different ways, where printf is active, therefore its processing
and in the second form where it is in sleep mode, thereby after executing the sleep call
in either of the case, whatever be the state of the program that is in memory when kernel delivers a signal to the process,
if the signal handler is registered with a function 'f' it would be executed else default action of the delivered signal would be executed.
well, I was suggested to remove the contents of the cache as i get out of the browser netscape from the .netscape folder. is that really necessary? if so what are the rest to be done?
can anybody please tell me?:rolleyes: (8 Replies)
:) Hello, i have been given the following code to help me learn how to use signals, it won't compile. The problem maybe because this was written for use in Unix and i am trying to compile in Linux.
The error i get says that SIGPIPE and SIG_IGN are undeclared.
I think that these are defined... (2 Replies)
Hello,
I have created following alias in csh
lab 'rlogin -l user23 complab23'
but problem is complab23 does not allow automatic login by checking .rhosts file. So after typing lab on command line I have to type complicate password and if wrong password is typed thrice then account gets... (4 Replies)
Wasn't really sure where to put this, since I'm using C in UNIX, but I am making my own shell... so, what's going on is this:
For our program, we had to create our own shell, and if the user pressed ctrl-c just at the cmdline, then this signal would be ignored, but if there is a foreground... (1 Reply)
Whats a signal 0. An exhaustive search on signals landed me nowhere.
Is it possible to do something like this trap "echo $var" 0.
If so what signal does this trap catch ? (2 Replies)
awk "/^<Mar 31, 2012 : /,0" /app/blah.log
can someone please help me figure out why the above command isn't pulling anything out from the log?
basically, i want it to pull out all records, from the very first line that starts with the date "Mar 31, 2012" and that also has a time immediately... (4 Replies)
hi,
iam perl begginer,i have written the program
#!/usr/bin/perl
#use warnings;
use strict;
print "Enter the name:","\n";
my $name=<STDIN>;
my %hash=(siva => "9902774481",
dev => "9916391244",
venky => "9440506760",
manohar => "9440232695"
);
print "$name no is:... (5 Replies)
If I run a script called 'abc.sh' and then execute the following :
ps -ef | grep 'abc.sh'
I always get two rows of output, one for the executing script, and the other for the grep command that I have triggered after the pipe.
Questions: Why does the second row turn up in the results. My... (10 Replies)
awk -F ";" 'FNR==NR{a=$1;next} ($2 in a)' server.list datafile | while read line
do
echo ${line}
done
when i run the above, i get this:
1 SERVICE NOTIFICATION: nagiosadmin skysmart-01.sky.net ....
instead of:
SERVICE NOTIFICATION: nagiosadmin skysmart-01.sky.net ....
can... (4 Replies)
We have huge file with control A as delimiter. Somehow one record is corrupted. This time i figured it out using ETL graph. If future , how to print only bad record.
Example Correct record:... (2 Replies)
Discussion started by: srikanth38
2 Replies
LEARN ABOUT DEBIAN
sigtrap
sigtrap(3perl) Perl Programmers Reference Guide sigtrap(3perl)NAME
sigtrap - Perl pragma to enable simple signal handling
SYNOPSIS
use sigtrap;
use sigtrap qw(stack-trace old-interface-signals); # equivalent
use sigtrap qw(BUS SEGV PIPE ABRT);
use sigtrap qw(die INT QUIT);
use sigtrap qw(die normal-signals);
use sigtrap qw(die untrapped normal-signals);
use sigtrap qw(die untrapped normal-signals
stack-trace any error-signals);
use sigtrap 'handler' => &my_handler, 'normal-signals';
use sigtrap qw(handler my_handler normal-signals
stack-trace error-signals);
DESCRIPTION
The sigtrap pragma is a simple interface to installing signal handlers. You can have it install one of two handlers supplied by sigtrap
itself (one which provides a Perl stack trace and one which simply "die()"s), or alternately you can supply your own handler for it to
install. It can be told only to install a handler for signals which are either untrapped or ignored. It has a couple of lists of signals
to trap, plus you can supply your own list of signals.
The arguments passed to the "use" statement which invokes sigtrap are processed in order. When a signal name or the name of one of
sigtrap's signal lists is encountered a handler is immediately installed, when an option is encountered it affects subsequently installed
handlers.
OPTIONS
SIGNAL HANDLERS
These options affect which handler will be used for subsequently installed signals.
stack-trace
The handler used for subsequently installed signals outputs a Perl stack trace to STDERR and then tries to dump core. This is the
default signal handler.
die The handler used for subsequently installed signals calls "die" (actually "croak") with a message indicating which signal was caught.
handler your-handler
your-handler will be used as the handler for subsequently installed signals. your-handler can be any value which is valid as an
assignment to an element of %SIG. See perlvar for examples of handler functions.
SIGNAL LISTS
sigtrap has a few built-in lists of signals to trap. They are:
normal-signals
These are the signals which a program might normally expect to encounter and which by default cause it to terminate. They are HUP,
INT, PIPE and TERM.
error-signals
These signals usually indicate a serious problem with the Perl interpreter or with your script. They are ABRT, BUS, EMT, FPE, ILL,
QUIT, SEGV, SYS and TRAP.
old-interface-signals
These are the signals which were trapped by default by the old sigtrap interface, they are ABRT, BUS, EMT, FPE, ILL, PIPE, QUIT, SEGV,
SYS, TERM, and TRAP. If no signals or signals lists are passed to sigtrap, this list is used.
For each of these three lists, the collection of signals set to be trapped is checked before trapping; if your architecture does not
implement a particular signal, it will not be trapped but rather silently ignored.
OTHER
untrapped
This token tells sigtrap to install handlers only for subsequently listed signals which aren't already trapped or ignored.
any This token tells sigtrap to install handlers for all subsequently listed signals. This is the default behavior.
signal
Any argument which looks like a signal name (that is, "/^[A-Z][A-Z0-9]*$/") indicates that sigtrap should install a handler for that
name.
number
Require that at least version number of sigtrap is being used.
EXAMPLES
Provide a stack trace for the old-interface-signals:
use sigtrap;
Ditto:
use sigtrap qw(stack-trace old-interface-signals);
Provide a stack trace on the 4 listed signals only:
use sigtrap qw(BUS SEGV PIPE ABRT);
Die on INT or QUIT:
use sigtrap qw(die INT QUIT);
Die on HUP, INT, PIPE or TERM:
use sigtrap qw(die normal-signals);
Die on HUP, INT, PIPE or TERM, except don't change the behavior for signals which are already trapped or ignored:
use sigtrap qw(die untrapped normal-signals);
Die on receipt one of an of the normal-signals which is currently untrapped, provide a stack trace on receipt of any of the error-signals:
use sigtrap qw(die untrapped normal-signals
stack-trace any error-signals);
Install my_handler() as the handler for the normal-signals:
use sigtrap 'handler', &my_handler, 'normal-signals';
Install my_handler() as the handler for the normal-signals, provide a Perl stack trace on receipt of one of the error-signals:
use sigtrap qw(handler my_handler normal-signals
stack-trace error-signals);
perl v5.14.2 2011-09-19 sigtrap(3perl)